The present invention relates to an apparatus for rectifying current. The invention more particularly relates to CMOS circuitry for rectifying current in a continuous time domain.
Many current rectifiers are known in the art. One group of current rectifiers which are known to those skilled in the art utilize at least one operational amplifier, one comparator, and numerous resistors. These current rectifiers are typically used in switching networks where the relative reacting speed is not critical. Another set of current rectifiers known to those skilled in the art are those rectifiers using diodes. While the simplest diode current rectifiers do not account for the forward voltage drop across the diode, other arrangements known in the art have accounted for the same. However, diodes are not advantageously used in CMOS circuitry because of the resulting creation of parasitic vertical pnp transistors. Thus, it will be appreciated that the current rectifiers known in the art typically suffer from one or more of the inability to work in a continuous time domain; the inability to be integrated into a CMOS design; and the requirement of many components.